Existing network architectures for high-density distributed data centers use several flat Layer 2 (i.e., a data link layer of the seven-layer Open Systems Interconnection (OSI) model) Ethernet networks for connecting servers of the data centers. The servers in the data centers need to be connected to the same broadcast domains to allow live migration of virtual machines (VMs) provided within the servers. A virtual machine is a software implementation of a machine (e.g., a computer) that executes instructions like a physical machine. System virtual machines permit sharing of underlying physical machine (e.g., server) resources between different virtual machines, with each system virtual machine running its own operating system. A software layer providing the virtualization is called a virtual machine monitor or hypervisor. A hypervisor can run on hardware or on top of an operating system.
Servers located in remote data centers may typically be connected using Layer 2 tunnels (e.g., virtual private local area network (LAN) service (VPLS) tunnels or Layer 2 virtual private network (L2VPN) tunnels). Network components (e.g., network interfaces) of data center servers may tie together Layer 2 and Layer 3 (e.g., a network layer of the OSI model) network elements. In order to communicate with one another, the data center servers need to use or maintain Address Resolution Protocol (ARP) tables to locate media access control (MAC) addresses of other servers in the data center. ARP is a computer networking protocol for determining a network host's Layer 2 or hardware address when only the host's Internet Layer or Layer 3 address is known. The ARP tables help translate an Internet protocol (IP) address to a MAC address in order to assist in encapsulation of IP packets to Ethernet frames.